1. Field of the Invention
The present invention relates to a golf club head having excellent hitting sound and improved directional stability of a hit ball, and a golf club using the golf club head.
2. Description of the Background Art
In recent years, it has been known an attempt to lower the center of gravity of the golf club head to improve flight distance of a hit golf ball. Such a golf club head comprises a fiber reinforced resin member, whose specific gravity is smaller than a metal material such as a titanium alloy and the like, for example, in a crown portion and/or a sole portion. However, in such a combined type of a golf club head, the moment of inertia Ic (shown in FIG. 2) about an axial center line CL of a club shaft (such moment of inertia may be hereinafter simply referred to as “moment of inertia”) tends to be small, depending on a position where the fiber reinforced resin is provided. For such a golf club head with the small moment of inertia Ic, there was a problem that orientation of a club face was not stable during swinging, and thus directional stability of a hit golf ball easily degraded.
For such a golf club head, there was also a problem that hitting sound became significantly low depending on a position where the fiber reinforced resin was provided, thereby degrading impact feeling.
The inventor, et. al conducted various experiments on the problems described above. As a result, when the club head is viewed from the sole side while the head being in a standard state in which the head is disposed on a horizontal plane so that a center line of a club shaft is inclined at the lie angle within a vertical plane and a club face forms its loft angle with respect to the vertical plane, it was revealed that the center of gravity of the head in the sole portion is a location subject to large vibration at the impact of the ball. Then, it was learned that provision of fiber reinforced resin in any location other than a location subject to large vibration is effective in improvement of the impact feeling.